DM385: u-boot spi load

Hi German,

If you are using DM38x IPNC RDK, seems that SPI boot is not supported by default, we have SD and NAND boot:

http://processors.wiki.ti.com/index.php/IPNC_RDK_DM38x_,_DM8127

For SPI boot, you might need some u-boot source code modifications. You can refer to below guides for hints:

http://processors.wiki.ti.com/index.php/TI81XX_PSP_UBOOT_User_Guide

DM38x TRM, ch 4 ROM Code Memory and Peripheral Booting

Note that this product does not have ongoing direct TI design support. For detailed support while working through your design, you may contact one of the following third parties: D3 Engineering, elnfochips, Ittiam Systems, Path Partner Technology, or Z3 Technologies.

Regards,
Pavel

Thanks a lot for quick response.

Just one more clarification before closing the case:

I think at the described moment processor is controlled not by u-boot yet,

but by ROM bootloader code.

Is it possible to look through ROM bootloader text, at least its SPI brunch?

Regards

Thanks, Pavel

By no means I wanted to modify ROM boot code.

It's just an issue of understanding of proper order of SPI load.

It looks like I can't correctly follow procedure described in datasheet and tech reference.

(so probably just an issue of my stupidity)

Nevertheless, from all descriptions of memory booting (including SPI)

I got an impression that Image for loading has to have just one header, containing size and address.

Simple experiments with content of my SPI image show me that EVERY 512-byte page has to

present some kind of header to make processor to read next 512-byte piece. (By changing first

bytes of next 512-page I can force processor to read more pages)

One can find a nice piece of information in Tech Ref, "SPI Read Sector Procedure"

"From the next iteration onwards, a dummy value is transmitted on the master out line and the data is
received on the master in line. This needs to be done because SPI protocol always operated in full duplex
mode. The dummy data transmitted by the ROM is the Read Command appended to the start address"

But this sentence is not enough for me to understand completely what should be transmitted every page.

Has the start address be always the initial one or 512-byte shifted for every page? Or it doesn't matter,

since it's "dummy" operation? And what about file size required for header - is it still in force?

I, probably can spend some time experimenting and finally figure out, how to load device from SPI,

But it would be very helpful if TI can submit me with more detailed info then one sentence in tech ref.

One way of understanding it, was following ROM boot code, that's why I asked about it.

And yes, I understand that DM38x is kind of abandoned child and don't have a lot of expectations.

Best regards

Hello!

Excuse me, I didn't understand completely:

ROMboot is not available for modification, but is it available for viewing?

I remember for DM365 it was quite possible to overview romboot code,

Thanks